diff --git a/clients/lcdproc/machine_Linux.c b/clients/lcdproc/machine_Linux.c
index 2e53fea..d197ff2 100644
--- a/clients/lcdproc/machine_Linux.c
+++ b/clients/lcdproc/machine_Linux.c
@@ -497,8 +497,16 @@ int machine_get_smpload(load_type *result, int *numcpus)
 
 int machine_get_uptime(double *up, double *idle)
 {
+	double local_up, local_idle;
+	
 	reread(uptime_fd, "get_uptime:");
-	sscanf(procbuf, "%lf %lf", up, idle);
+	sscanf(procbuf, "%lf %lf", &local_up, &local_idle);
+	if (up != NULL)
+			*up = local_up;
+	if (idle != NULL)
+			*idle = (local_up != 0)
+				? 100 * local_idle / local_up
+				: 100;
 
 	return(TRUE);
 }